Roasting-furnace for sulfur-bearing ores.



H. H. STOUT. ROASTING FURNACE F011 SULFUR BEARING oRES.

APPLICATION FvlL\ED JUNE 5.1915. 1,181,184.

Patented May 2, 1916.

2 SHEETS-SHEET I.

A v URNEYS H. H. STOUT.

ROASTING FURNACE FOR SULFUR BEARING ORES.

APPLICATION FILED JUNE 5.1915.

Lll. 'Patented May 2,1916.

2 SHEETS-SHEET 2.

WMQ@ v f Ano/mns INI/ENTOR Taz/ sra'rns @Parana carica.,

HARRY H. STOUT, 0F NEW YORK, N. Y., ASSIGNOR T0 GENERAL CHIEICA CUMPNY, 0F NEW YORK, N. Y., A CORPORATION 0F NEW YORZIv Specicatiop of Letters Patent.

i ROASTING-FURNAC FOR SULFUR-BEARING GRES.

Patented May 2, 1916.

Original application led July 31, 1914, Serial No. 854,230. Divided and this application led June 5, 1915.

Serial No. 32,251. v

To all whom t'mag/ concern:

Be it known that I, HARRY I-I. SToU'r, a citizen of the United States, and a resient of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Roasting Furnaces for Sulfur Bearing Ores, of which the following, taken in connection with the accompanying drawings, is a specification. 1

My invention relates to the roasting of sulfur-bearing ores, especially in connection with a rotary roasting furnaceof the type shown in United States Letters Patent, No. 976,175 to John B. F. Herreslioff, dated November 22, 1910, and the object of my invention is to provide a regulatable distribution of heat, and controllable temperature conditions on each of the several roasting hearths or shelves of such a furnace and to provide a furnace structure capable of admitting of such controllable operation. Y

This application is a division of my application, Serial Number 854,230, filed. July` It has long been known that an obstacle to the most economical and eflicient operation of furnaces of this type is the formation of incrustations which clog up the moving parts of the furnace, or of scars, e. fused masses of the material undergoing roasting, which attach themselves with more or less firmness to the hearth surface or to the rabble teeth or to both, thus bringing about ineiiciencies in operation due to stoppage and due to the physical condition of the agglomerated material, which renders it incapable of being deprived of its sulfur content to the extent necessary for'successful commercial operation. These scars or incrustations usually form in the upper hearth spaces the temperature of which is apt to be excessively high while the lower hearth spaces are 'at the same time at a temperature which is usually too low for eilicient operation. If, as has'been proposed, the furnace is operated at below normal capacity, the formation of these agglomerated masses may to some extent be prevented, but such operation is obviously inefficient and is not capable of being controlled.

I have found that by a proper transfer of l the heat generated on any hearth in excess of that heat necessary to bring about satisfactory roasting, to some other hearth having insufficient heat or temperature conditlons, satisfactory roasting can be effected,

coupled with a capacity per day greater than under the most favorable conditions hereto- Figure l shows the furnace in central ver-` tical section,` and Fig. 2 shows a plan View thereof, certain parts being in section.

The .furnace illustrated comprises a number of superposed hearths 1 extending inwardly from an outer, cylindrical wall 2 and providing roasting spaces between the hearths,- which spaces are traversed by rabble .or 4stirring arms 3, rotatably supported by a-central, vertical double-walled shaft 4. Through the central passage of the shaft, air or other suitable cooling medium is forced, from which passage it passes through the several rabble arms in parallel and issues therefrom into the annular passage of the shaft, which surrounds the central passage thereof.

In communication with the top of the annular channel of the shaft is a transverse conduit 5, the ends of which connect with the bustle pipe 6, the latter being in the form of a ring of approximately the same diameter as the furnace itself and being supported upon the cylindrical wall 2 of the furnace. The bustle pipe communicates with a plurality of vertical lues or conduits 7, preferably metallic, which are built into the wall 2, so that their inner walls are inl direct contact with the products of roasting in the furnace hearth-spaces and which extend from the bustle pipe to the lowest hearth-space. Air or other iiuid is thus ca- .of them may discharge into other roasting roasting spaceof.- According to each method of.opera of heatfrom the furnace by being forced.

An outlet into the atmosphere is provided vin the form `of a stack 8 which may extend upw'adly from the transverse conduit 5 and is pr vided with-a valve or damper A pipe 9 insulated from the heat of the furnace, or-'a plurality of such pipes, connects with the conduit 5- and 'extends downwardly; the lower end of said pipeis in communication with the inlet conduit '10 which communicates at one end with the" central' passage of the shaft 4 and which is adapted to convey cooling air from a fan or other uid-for'cin apparatus (not shown) into the shaft/an if desired, into the pipel 9, the latter preferably communicating with the conduit 10 at a point located between the fan andthe shaft. A branch pipe 11 establishes communication'between each pipe 9 and one or more of the roasting spaces, as for example, that of the lowermost hearth into which the ues or conduits7 also discharge. v

The transverse conduit 5 is provided with dampers b located between the shaft 4 and the outlet 8 on the one hand andthe bustle pipe 6 and the pipe 9 on the other hand. Dampers c are provided betweenthetransverse conduit and the bustle pipe; dampers d and e are provided in the pipes 9 respectively-above and below the point of commulThe device illustrated is adapted to be operated in a,.numberl of ways which will depend upon the nature and qualities of the ore being roasted, which ores may be, for example, iron pyrites, copper pyrites, pyhrro` tite, blende, galena or various mixtures theretion, however, air, or other suitable cooling Huid, which has extracted a certain amount through the rotary stirring system is passed into,heat exchanging proximity to the hotter portions of the furnace and discharged into cooler portions thereof, soas to conveyh heat from saidhotter portions to said cooler portions and because of its preheated condition, to augment ro-asting in said cooler portions. In other words, `the coolingl air, after it has traversedv the shaft and rabble arms of the rotary stirring system, is caused to pass through the conduits 7 and to extract heat from the upper roasting spaces due to the fact that said conduits are'made of material which conducts heat readily said material being exposed to and in direct conduits'7, finally discharging into the lower hearth space. If desired, the damper a may be opened slightly and if necessary the dampers b and 0 be closed slightly so as to cause any proportion of the air to pass from the transverse conduit into the atmosphere through the stack 8, Yand the remainder toV pass through the conduits 7 into the lowermost combustion chamber. Further heat control may be had by opening the dampers d and f more or less and closing the damper e, the damper a, being either open or closed, so that a portion of the air will pass down through the pipe 9 into the branch 11 and discharge into the lower hearth space.

It is obvious that'a suitable manipulation of the dampers will result ,in causing all of -the air to pass into the atmosphere through the exit 8, all of it to pass through the heat interchanging conduits 7 into the lower portions of the furnace, all of it to pass through the external pipe 9 into said lowerportions,

all of it to pass through any two of these passages 7, 8 and 9, or any proportion of it to pass through these two or three passages.

It will be seen that the furnace is very iexi ble in its operation and can be accommo .10b

dated to the roasting of any kind of ore. It is further possible to manipulate the dampers in an obvious manner so as to cause all of the cooling air to pass from the rotary mechanism through the exit stack whileat the same time air is caused to flow directly fromthe conduit 10 into the pipe 9 and from said pipe either directly into the lower chamber in non-'heated condition or through the heat exchanging conduits 7 into said chamber, the air in the latter case being preheated before passing -into said chamber and serving to` regulate andv control the heat and temperature of the furnace by `extracting heat from the upper portions of the furnace,

outer, cylindrical wall a plurality offsuperyposed .roasting chambers and a rotary aircooled rabble system, the combination of a metallic downwardly extending conduitf i the external surface of said conduit being exposed to the atmosphere of certain of said roasting chambers and the lower end thereof being in communication with the lowermost of said chambers, and means for conducting air from the upper end of the rabble system to the upper end of said conduit, substantially as and for the purpose described. y

2. In an ore roasting furnace having an outer, cylindrical wall a plurality of superposed roasting chambers and a rotary aircooled rabble system, the combination of a metallic, downwardly extending conduit the external surface of said conduit being exposed to the atmosphere of certain of said roasting chambers and the lower end thereof being in communication with the lowermost of said chambers, valved means for conducting air from the upper end of the rabble system to the upper end of said conduit, and valved means for conducting air from the upper end of the rabble systern into the atmosphere, substantially as and for the purpose described.

3. In an ore roasting furnace having an outer, cylindrical wall a plurality of superposed roasting chambers *and a rotary aircooled rabble system, the combination of a metallic, downwardly extending conduit the external surface ofvsaid conduit being exposed to the atmosphere of certain of said roasting chambers and the lower end thereof being in communication with the lowermost of said chambers, means for conducting air from the upper end of the rabble system to the upper end of said conduit, and a conduit insulated from the'heat of the furnace, for conducting air from the upper end of the rabble system to the lowermost of said chambers, substantially as and for the purpose described.

4. In an ore roasting furnace having an outer, cylindrical wall a plurality of superposed roasting chambers and a rotary aircooled rabble system, the combination of a metallic, downwardly extending conduit the external surface of said conduit being exposed to the atmosphere of certain of said roasting chambers and the lower end thereof being in communication with the lowermost of said chambers, valved means for conducting air from the upper end of the rabble system to the upper end of said conduit, valved means for conducting air from the upper end of the rabble system into the atmosphere, and a valved conduit insulated from the heat of the furnace, for conducting air from the upper end of the rabble system to the lowermost of said chambers, substantially as and for the purpose described.

5. In an ore roasting furnace having an outer, cylindrical wall, a plurality of superposed roasting chambers and a rotary, aircooled rabble system, the combination of a cylindrical system of metallic, vertically extending conduits within said cylindrical wall, a surface of each of said conduits being exposed to the atmosphere of certain of said roasting chambers and the lower ends of said conduits being in communication with one of said chambers, and means for conducting air from the upper end of the rabble system to the upper ends of said conduits, substantially as and for the purpose described. y

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

HARRY H. STOUT. Witnesses: i

JOHN A. FERGUSON, FRED A. KLEIN. 

